Tabrizicola aquatica gen. nov. sp. nov., a novel alphaproteobacterium isolated from Qurugöl Lake nearby Tabriz city, Iran

A novel Gram-negative, aerobic, non-motile and rod-shaped bacterium was isolated from Qurugöl Lake near Tabriz city. The bacterium grew chemoorganolheterotrophically and chemolithoautotrophically. However, photo-organoheterotrophic, photo-lithoautotrophic and fermentative growth could not be demonstrated. The presence of photosynthesis genes pufL and pufM was not shown and photosynthesis pigments were not formed. Strain RCRI19^T grew without NaCl and tolerated up to 3 % NaCl. Growth occurred at pH 6–9 (optimum, pH 7) and 15–55 °C (optimum 40–45 °C). Vitamins were not required for growth. The major fatty acids are C_18:1 ω7C, 11-methyl C_18:1 ω7C, C_18:0 3-OH. The predominant respiratory quinone is ubiquinone Q-10. The G+C content of genomic DNA is 65.9 mol%. Analysis of 16S rRNA sequences showed that strain RCRI19^T has the highest similarities with uncultured environmental sequences followed by members of the genera Rhodobacter (≤95.75 %), Haematobacter (≤95.53 %), Gemmobacter (≤95.17 %) and Falsirhodobacter (94.60 %) in the family Rhodobacteraceae. DNA–DNA relatedness between strain RCRI19^T and the closest phylogenetically related strain, Rhodobacter blasticus LMG 4305^T, was 20 %. Based on its phenotypic and chemotaxonomic characteristics and considering that it does not form photosynthetic pigments and is unable to grow phototrophically, it is concluded that strain RCRI19^T cannot be included into the genus Rhodobacter and any of the other related genera. Therefore, we propose to place the new bacterium into a new genus and species for which the name Tabrizicola aquatica gen. nov. and sp. nov. is proposed. The type strain is RCRI19^T (=BCCM/LMG 25773^T = JCM 17277^T = KCTC 23724^T).     

The discovery of novel isoflavone pan peroxisome proliferator-activated receptor agonists

Twenty three dual PPARα and γ molecules of natural product origin, previously reported by our group, were further investigated for pan PPAR transactivation against PPARδ. The in vitro cell toxicity profile, as well as, in silico study of the most active molecules within this new class of pan PPAR agonists are also described. 3′,5′ Dimethoxy-7 hydroxyisoflavone 6, Ψ-baptigenin 7, 4′ fluoro-7 hydroxyisoflavone 8, and 3′ methoxy-7 hydroxyisoflavone 9 were identified as the most potent molecules studied within the set compared to the commercially available pan PPAR agonist, bezafibrate 1. These novel active molecules may thus be useful as future leads in PPAR-related disorders, including type II diabetes mellitus and metabolic syndrome.     

Localized Surface Plasmon Resonance (LSPR)-Based Nanobiosensor for Methamphetamin Measurement

Aptamers are DNA or RNA single-stranded molecules that bind specifically to target molecules with high affinity. Function of nucleic acid aptamers is based on organized tertiary structure of them that is related to primary sequence, length of nucleic acid molecule, and environmental conditions. Herein, a localized surface plasmon resonance (LSPR) nanobioprobe has been developed based on specific aptamer-conjugated gold nanoparticles for rapid detection of methamphetamine. Detection of methamphetamine was studied via monitoring the gold nanoparticles (GNPs) LSPR band alterations in the presence of different concentrations. The covalent conjugation has been confirmed with FT-IR spectroscopy, and size alterations of gold nanoparticles before and after the conjugation state were monitored using dynamic light scattering (DLS) technique. The results show high affinity of aptamer to methamphetamine. Moreover, the results show conjugated aptamer with GNP in different concentrations of methamphetamine that contribute to color changes that is visible with unaided eye. Also, 14 nm LSPR shift was seen after conjugation of aptamer with GNP. Nanoparticle diameter after conjugation with aptamer was increased from 30 to 91 nm and decreased after incubation with methamphetamine (due to folding) from 91 to 84 nm. Detection limit of this designed nanoprobe is 500 nM. Plasmonic nanoparticle-based nanobioprobe is a new field for development of sensitive detection systems.

     

Bioassay evaluation of the entomopathogenic fungus,Lecanicillium longisporum (Petch) Zare & Gams against egg and nymphs of Trialeurodes vaporariorum Westwood in laboratory conditions

Abstract

This study was carried out to determine the lethality of the entomopathogenic fungus, Lecanicillium longisporum on eggs, young and old nymphs of the greenhouse whitefly, Trialeurodes vaporariorum. Mortality percentage was significantly differed based on stage of T. vaporariorum and conidial concentrations of L. longisporum. Average of the infection level to insect was very low particularly in egg with only 9.81%, even with higher conidial concentrations (1×10⁷ conidia mL^-1). Whereas, it was higher in 1^st and 2^nd instar (46.56%) and 3^rd and 4^th instars (37.21%). Three parameters were assessed with T. vaporariorum eggs, namely; egg infection, egg hatchability and crawlers emergence. Egg mortality percentages averaged 3.56, 7.14, 9.64, 16.42 and 20.35% with fungal concentrations of 1×10³, 1×10⁴, 1×10⁵, 1×10⁶ and 1×10⁷ conidia mL^-1, respectively. Daily infection percentages were varied depend upon the conidia concentration where the highest infection rate of eggs was occurred with 1×10⁷. Egg hatch was very high and the mortality among the emerged crawlers was neglectable compared with the control. Efficiency of L. longisporum on whitefly nymphs also was varied based on the insect instar and fungal concentration. Mortality percentages were obviously higher in young nymphs (1^st and 2^nd instars) than in older ones (3^rd and 4^th instars). The results indicated that nymphs were highly susceptible to fungal treatment compared with eggs.     

Effect of polyamines on the structure, thermal stability and 2,2,2-trifluoroethanol-induced aggregation of alpha-chymotrypsin

Naturally occurring polyamines are known to interact with a variety of biomolecules and critically involve in some important physiological processes. They have also been shown to influence protein aggregation in vitro in some cases. The aim of the present study was to investigate how polyamines may influence the structure and thermal stability of alpha-chymotrypsin and modulate alcohol-induced aggregation of this protein. Various techniques, including turbidity measurements, tensiometry, DSC, intrinsic fluorescence and far- and near-UV circular dichroism spectroscopy were used to examine the effect of putrescine and spermidine on alpha-chymotrypsin. While slight changes in the secondary and tertiary structure of the protein was observed, a clear stabilizing effect against its thermal unfolding was achieved. Moreover, the polyamines were found to inhibit TFE-induced aggregation at 32% TFE and promote formation of non-native alpha-helices in the protein structure. Based on the observed increase in surface tension induced by polyamines, it is suggested that their effects on enhancing thermal stability and alcohol-induced alpha-helices formation may be due to their kosmotropic properties.     

Abnormal hair development and apparent follicular transformation to mammary gland in the absence of hedgehog signaling

We show that removing the Shh signal tranducer Smoothened from skin epithelium secondarily results in excess Shh levels in the mesenchyme. Moreover, the phenotypes we observe reflect decreased epithelial Shh signaling, yet increased mesenchymal Shh signaling. For example, the latter contributes to exuberant hair follicle (HF) induction, while the former depletes the resulting follicular stem cell niches. This disruption of the niche apparently also allows the remaining stem cells to initiate hair formation at inappropriate times. Thus, the temporal structure of the hair cycle may depend on the physical structure of the niche. Finally, we find that the ablation of epithelial Shh signaling results in unexpected transformations: the follicular outer root sheath takes on an epidermal character, and certain HFs disappear altogether, having adopted a strikingly mammary gland-like fate. Overall, our study uncovers a multifaceted function for Shh in sculpting and maintaining the integrity and identity of the developing HF.